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llewelly
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 Posted: Wed Apr 21, 2004 3:54 pm Post subject: Re: alternative tokens |
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[email]ank (AT) despammed (DOT) com[/email] (Alexander Krotov) writes:
[snip]
| Quote: | Further, section 2.12 says:
preprocessing-op-or-punc: one of
..
new delete ...
and and_eq bitand bitor compl not not_eq or or_eq
xor xor_eq
..
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Reserved words such as new and delete are different from alternative
tokens. Reserved words are unconditionally treated as keywords in
phase 7, but recieve no special treatment in phase 4, where
preprocessing directives are executed and macros are
expanded. (See section 2.1, as well as 2.12 .)
| Quote: |
Does this mean that "new", "delete", as well as alternative tokens
cannot be used as macro names (as they are preprocessing-op-or-puncs,
not identifiers) ?
Section 2.12 says:
2 In all respects of the language, each alternative token behaves the
same, respectively, as its primary token, except for its spelling5).
The set of alternative tokens is defined in Table 2.
Does this mean that alternative tokens can be used in preprocessor
conditional include conditions (#if) ?
Test:
#define not_eq X
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ill-formed.
| Quote: | #define new delete
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well-formed.
| Quote: |
not_eq
new
#if 1 and 2
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well-formed, condition is true.
| Quote: | Foo.
#endif
#if 1 not_eq 2
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well-formed, condition is true.
| Quote: | Bar.
#endif
GCC 3.3 complains:
tp.c:1:9: "not_eq" cannot be used as a macro name as it is an operator in C++
and understands alternative tokens in #if conditions.
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GCC is correct here. It is also correct to accept the two #if
preprocessoring conditionals.
| Quote: | ICC 8.0 (as far as I know EDG based) complains
tp.c(9): error #14: extra text after expected end of preprocessing directive
#if 1 not_eq 2
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ICC is wrong in this case.
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